There are a multitude of both civilian and military applications needing precise timing and timekeeping. There is considerable interest is so-called chip-scale atomic clocks exploiting quantum effects and having stabilities of the order of 1E-12 for simple thermal atom clocks to 1E-16 in the case of optical lattice clocks. The applications of compact atomic clocks are vast and include:
1. Autonomous navigation, e.g., automotive, maritime, aviation, personal;
2. Space, e.g., micro satellites;
3. Communications, e.g., cellular systems, telecommunications networks, military radio;
4. Finance, e.g., high-frequency computer based trading, data security
The QFC project is a direct response to the challenges outlined in the UK Quantum Technology Landscape 2014 (Pritchard & Till, 2014). The project is the first step towards transforming the new quantum clock technologies from research laboratory experiments into engineered solutions. The new quantum clock technologies, encompassing thermal atom, trapped single cold-atom and trapped multiple cold-atom physics are disruptive innovations. Such clocks will create new markets and applications through both their improved stability and also potential reduction in size, weight, power and cost.
To reap the benefits of the new quantum science innovation, engineering innovation is now required. The understanding and behaviour of quantum clock physics has been obtained in the well-defined, benign confines of a laboratory, using general-purpose equipment. The challenge now is to develop robust physics packages able to withstand the end-user environment while optimising the electronic systems for performance, power, mass, volume and cost. Recognising the variety of applications for the new quantum clocks, the approach of QFC includes a number of innovations to maintain flexibility. There will likely not be a single optimum solution for any application; one may wish to have best performance (highest stability) or best efficiency (lowest power). QFC will allow the user to choose. There are no current commercial clocks with such capabilities.